Ater the job interview, you will need to do some 'follow-up' with the recruiter[s].  This section provides sample of the expected follow-up letters:

Thank You - thank the recruiter for the opportunity to interview with the company, and 'that you hope to hear back from him/her/them soon'.

Acceptance - Yea! You got the job offer.  You should submit a letter 'formally accepting the offer'.

Withdrawal - Things can change between the time you've interviewed and before you hear back from the company.  If you won't be able to accept the job offer, you should submit a letter as soon as possible notifying the recruiter[s] about this.

Rejection - If the job offer isn't what you'll accept, you need to 'professionally' reject the offer.  You never know when you might interview with the company or recruiter[s] again in the future.  You need to be as professional as possible.